24 lines
493 B
C
24 lines
493 B
C
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#include <stdio.h>
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#include <fcntl.h>
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#include <io.h>
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void main()
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{
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int handle;
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char buffer[20];
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handle = open( "file", O_RDWR | O_TEXT );
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if( handle != -1 ) {
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if( lock( handle, 0L, 20L ) ) {
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printf( "Lock failed\n" );
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} else {
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read( handle, buffer, 20 );
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/* update the buffer here */
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lseek( handle, 0L, SEEK_SET );
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write( handle, buffer, 20 );
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unlock( handle, 0L, 20L );
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}
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close( handle );
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}
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}
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